How do I remove the plastic fin from top of Dragonfly transducer?

[Jim_MI]

Chuck -
I just got a new kayak with a "Lowrance Ready" hull. This will require some plastic surgery in order to fit my Dragonfly 5 Pro transducer into the Lowrance well and cover plate. That means that I must remove the vertical plastic fin that ordinarily connects the Dragonfly transducer to the transom mount. I don't recall if this unit came out of the box pre-assembled or if I slid the fin into the grooves on top of the transducer and it clipped in place somehow. At any rate, the vertical plastic fin does NOT want to simply slide off. I lubricated the slide joint and can get it to move back-and-forth 1-2 mm, but I don't want to force it without better understanding how these 2 pieces of plastic are held together so tightly. Is there some locking tab or trigger that I need to spring loose? How???